Dyeing cellulose derivatives and aftertreating for improved washfastness



Anthony B. Conciatori, New Providence, Fred Fortess, Summit, and VictorS. Salvin, New Providence, NJ.,

'assignors to Celanese Corporation of America, New

York, N.Y., a corporation of Delaware No Drawing. Application May 17,1954 Serial No. 430,411

3 Claims. (Cl. 8-74) This invention relates to dyeing and relates moreparticularly to the dyeing of cellulose acetate to produce coloredmaterials of improved washfastness.

As is well known, textile materials having a basis of cellulose acetateand other organic derivatives of cellulose'are generally dyed by meansof aqueous dyebaths containing dyestuffs of the type known as dispersedcellulose acetate dyestuffs. However, the fastness to washing of theresulting colored materials has not been as good as desired. Forexample, for certain purposes it is necessary to have colored materialswhichare substantially fast to washing at 120 or 130 F. The celluloseacetate textile materials dyed in the usual manner with dispersedcellulose acetate or the substantially acetone-insoluble. celluloseacetates of very high acetyl value such as the" cellulose acetatedyestuffs are not substantially wash fast at these temperatures.

It is, therefore, an object of this invention to provide a novel methodfor the dyeing of textile materials having a basis of cellulose acetateor other organic derivatives of cellulose, which will be freefrom theforegoing and other disadvantages.

Anotherobject of this invention is to provide a new method of dyeingtextile materials having a basis of cellulose acetate with dispersedcellulose acetate dyes to produce colored materials which aresubstantially fast to washing at 120 or 130 F.

Other objects of this invention will be apparent from the followingdetailed description and claims.

In accordance with this invention textile material having a basis ofcellulose acetate or other organic derivatives of cellulose is dyed witha dispersed cellulose acetate dyestufi carrying a reactive group orgroups and the dyed textile material is then treated with a soluble,heat-curable amidogen-formaldehyde condensate formed by the condensationof formaldehyde and a compound containing a reactive NH group, such asurea, cyclic ethylene urea, or melamine. Thereafter, the textilematerial is cured by heating to effect a reaction in the fibers betweenthe dyestufi and the amidogen-formaldchyde condensate. For best resultsthis reaction should be carried out in the presence of a catalyst.

The process of this invention is applicable to textile materialsconsisting essentially of cellulose acetate or other organic derivativesof cellulose such as cellulose esters, e.g. cellulose propionate,cellulose butyrate, cellulose acetate-propionate or celluloseacetate-butyrate, and

cellulose ethers, e.g, ethyl or benzyl cellulose. The process of thisinventionmay also be applied to textile materials comprising blendsof-fibers of cellulose acetate, or other organic derivatives ofcellulose, with fibers of other materials, such as regeneratedcellulose, e.g. viscose rayon or cuprammon-ium rayon; polyamides such asnylon, e.g. the polyamide of hexamethylene diamine and adipic acid or ofG-aminoca'proic acid; polyurethanes; acrylonitrile polymers andcopolymers; polyesters such as polyethylene terephthalate; cotton; andanimal fibers such as wool and mohair. However, it has been found to beparticularly suitable for the treatment of fabrics consistingessentially "ice of cellulose acetate, i.e. either the usualacetone-soluble triacetate, alone or in combinationwith regeneratedcellulose. It has also been found that the process of the presentinvention is suitable for the treatment of textile materials consistingessentially of other fibers dyeable' with dispersed cellulose acetatedyestuffs; thus, the application of the process of this invention toall-nylon: fabrics has resulted in an improvement in the washfast-' nessof the dyed fabrics.

The dispersed cellulose acetate dyestufis employed in the practice ofthis invention contain groups reactive with:

the amidogen-formaldehyde condensate. Such groups may be, for example,alcoholic or phenolic hydroxyl groups, unsubstituted amino groups, i.e.NH or monosubstituted amino groups, i.e. NHR where R is an aromatic oraliphatic radical having a carbon atom connected to the nitrogen atom.

Best results, that is the greatest degree of improvement in washfastnesscaused by the after-treatment with the amidogen-formaldehyde condensate,have been obtained when the dyestufi contains a plurality of alcoholicor phenolic hydroxyl groups, or both an amino group and a hydroxylgroup. For example, the treatment with the amidogen-formaldehydecondensate produces a marked improvement in the washfastness of thefollowing highly reactive blue dyestulfs: l,4-di(hydroxyethylamino) an-.

thraquinone, l,8-dihydroxy-4-p-(ls-hydroxyethyl)phenyl amino-S-nitroanthraquinone, 1,4-di(hydroxyethylamino)- 5,8-dihydroxy anthraquinone,l,5-dihydroxy-4-p-(a-hy droxyethyl)phenylamiuo- 8 nitro anthraquinone.The treatment also markedly improves the washfastness of the followinghighly reactive red azo dyestuffs: unsubstituted 4-nitrophenyl azo4-bis(fl-hydroxyethyl)aminobenzene and the same dyestuff carrying a2'-chloro substituent, or a 2'-methyl substituent, or both a 2-chloroand a 2'- methyl substituent, or a 2'-acetylamino substituent, or both a2-methoxy and a 2'-acetylamino substituent. There is also a markedimprovement in the washfastness of materials dyed with the highlyreactive pink dyestuffs, l-amino-4-hydroxy anthraquinone andI-amino-Z-methoxy-4-hydroxy anthraquinone, and the highly reactiveorange dyestuff 4-nitro-2,6-dichlorophenyl azo 4'-bis(/3- hydroxyethyl)amino-2--chlorob enzene.

Other suitable highly reactive dyestuffs for use in the practice of thisinvention are the yellow 2-nitro-4-sulfonamidodiphenylamines carryingalcoholic hydroxyl substituents. Examples of materials of this type arethe following novel yellow dyestufis: 2-nitrodiphenylamine-4-'substituent. Other examples of such materials are .the-

orange-yellow dyestuffs, 4'-ethoxy-Znitrodiphenylamide- 4-sulfon-amethyl {3 hydroxypropylamide and the 4'- ethoxy-2nitrodiphenylamine-4sulfon-a-hydroxymethylpropylamide, which are the subjects of thecopending ap-- plication of Adams and Salvin, Serial No. 430,408, filedon even date herewith, now abandoned. Especially good results withrespect to washfastness are obtained when there is employed the2-nitrodiphenylamine-4-sulfon (N it-hydroxyethyl) anilide described inthe copending application of Adams and Salvin, Serial No. 430,410, filedon even date herewith. v

Patented Mar. 31, 1959 The dyestuffs mentioned in the precedingparagraphs are of the highly reactive type. However, if desired, lessreactive dyestuifs may be employed in the practice of this invention.The degree of improvement in washfastness obtained when the lessreactive dyestuffs are used is smaller, but still significant. In thiscase, in order to obtain the desired degree of washfastness there shouldbe employed those of the less reactive dyestuffs which are themselvesintrinsically difficult to wash out of the cellulose acetate textilematerial. Thus, even. though the treatment with theamidogen-formaldehyde condensate effects a smaller degree of improvementin washfastness, the combination of this improvement and the intrinsicwashfastness of the dyed material results in a product having thedesired properties. Examples of suitable dyestuffs of this type are theyellow dyestuff, 2-nitro-diphenylamine-4-sulfonanilide and the reddyestulf, 4-nitro-2-methylsulfonephenyl azo4'-(N-B-hydroxyethyl-N-difluoroethyl) aminobenzene.

With certain dyestuffs a further improvement in the washfastness isobtained by combining the amidogenformaldehyde condensate treatment witha treatment with a metallic chelating agent, such as a copper-containingcondensation product. The use of the metallic chelating agent improvesthe washfastness of cellulose acetate dyed with those dispersedcellulose acetate dyestuffs which contain chelatable groups. Thus, theuse of the chelating compound improves the washfastness of celluloseacetate dyed with dispersed cellulose acetate dyestuffs having aplurality of --NH groups, or a plurality of phenolic hydroxyl groups, ora phenolic hydroxyl group and an -NH group, such as are present in theblue and pink dyestuffs listed above, wherein such groups are in theproper spatial relation for chelation to occur. For example, chelationin the anthraquinone dyestuffs is promoted when the phenolic hydroxylgroup or the amino group is peri to the carbonyl group of theanthraquinone, and, in the azo dyestuffs, when the hydroxy group isortho to the azo group. With such chelatable dyestuffs there is animprovement in washfastness even when the chelating agent is appliedas'the sole reactive treating agent, without the amidogen-formaldehydecondensate. However, in the latter case the extent of this improvementis generally less than when the amidogen-formaldehyde condensate is thesole treating agent, and is much less than when the two treatments arecombined. Also, although the chelating agent, when used alone, causesthe pink dyestuffs listed above and the blue dyestuffs 1,4,5,8-tetraaminoanthraquinone and 1,4 di Bhydroxyethylamino-5,S-dihydroxyanthraquinone to change markedly inshade, this change in shade is greatly diminished when the chelatingagent is used together with the amidogenformaldehyde condensate.

As stated, the process of this invention is highly useful in the dyeingof textile materials comprising blends of cellulose acetate, or otherorganic derivatives of cellulose, and cellulose fibers, particularlyregenerated ce1lulose fibers. The dispersed cellulose acetate dyestuffshave substantially no dyeing effect on regenerated cellulose.Accordingly, if it is desired to dye both components of the aforesaidblend it is necessary to employ an added dyestulf which has aflinity forthe regenerated cellulose, e. g. .a direct dyestuff. Advantageously, theadded dyestufi is of the type which is fixed on the regeneratedcellulose fiber by an aftertreatment with a cationic fixing agenttherefor. As is well known in the dyeing of cellulose such cationicfixing agents are commonly used in combination with metallic chelatingagents. Examples of suitable fixable direct dyestuffs are those soldunder the names Cuprofix Yellow ,GL (Pr. 526) Cuprofix Brown GL,CuprofixRubine BLN, Cuprofix Rubine FBL,

'Cuprofix Violet 2BL (Pr. 429), Cuprofix Navy Blue SL, Cuprofix BlueFGL, Cuprofix Blue LUL, Cuprofix Blue RUL, Cuprofix Black C concentrate"(Pr. 525), Cuprofix Black OB concentrate" (Pr. 147), Pontamine FastYellow 4GL (Pr. 53), Pontamine Fast Yellow RL, Pontamine Fast OrangeZRL, Pontamine Fast Orange RGL, Pontamine Fast Brown BL (Pr. 47),Pontamine Fast Red 6 BL (Pr. 428), Pontamine Fast Red 3BL, PontamineFast Violet 4RL (Pr. 277), Pontamine Fast Blue 3RL, Pontamine Fast BlueBLL, Pontamine Fast Blue CPL, Pontamine Fast Blue GGL (Pr. 432),Pontamine Black PGR (Pr. 372), Pontamine Diazo Black OR (Pr. 147). Thesedyestuffs are desirably incorporated into the aqueous dyebath togetherwith the dispersed cellulose acetate dyestuff.

Most of the yellow dispersed cellulose acetate dyestuffs do not have ahigh afiinity for nylon. Accordingly, when the process of this inventionis applied to blends containing nylon and cellulose acetate, otheryellow dyestuffs which are substantive to nylon should be employed.Examples of such nylon-substantive yellow dyestuffs are thepremetallized colors sold under the names Irgalan, e.g. Irgalan Yellow2RL, Cibalan and Capracy. These materials do not dye the celluloseacetate so that it is, therefore, necessary to use them in combinationwith a yellow dispersed cellulose acetate dyestutf where union dyeing isdesired. Another suitable type of yellow dyestuff, which has theadvantage of being substantive to both the cellulose acetate and thenylon when applied from an acidic medium, is the novel dispersedcellulose acetate dyestuff having the formula:

which is the subject of the copending application of Adams and Salvin,Serial No. 430,409, filed on even date herewith. This dyestuif has thefurther property of being highly reactive in the fiber with cationicmaterials, such as melamine-formaldehyde condensates, fixatives fordirect dyes, and copper-containing chelating agents, which cationicmaterials maybe employed for improving the washfastness of materialsdyed therewith.

The amidogen-formaldehyde condensates used in the practice of thisinvention are soluble, heat-curable materials of relatively lowmolecular weight formed by the condensation of formaldehyde and acompound containing a reactive -NH group, such as urea, melamine,ethylene urea, guanidine, dicyandiamide, guanyl urea or N-methyl urea.As is well known, the formaldehyde reacts at the NH group to produce anN-lydroxymethyl, i.e.

radical In the condensation products employed in the present inventionthis N-hydroxymethyl radical may be present as such, or may beetherified with a lower aliphatic alcohol such as methanol, ethanol,propanol or butanol, to form an N-alkoxymethyl radical. It is found thatthe amidogen-formaldehyde condensate is most effective when it is arelatively stable material containing a plurality of N-hydroxymethyl orN-allcoxyrnethyl radicals and has a cyclic, substantially monomericstructure. Also, it has been found that condensates containingN-methoxymethyl radicals are more effective than the correspondingN-hydroxymethyl compounds. Thus, the best results are obtained by theuse of condensation products of monocyclic ureas in which both nitrogensare joined, through carbon to nitrogen bonds, to a divalent aliphaticradical, e.g. ethylene urea, or by the use of condensation products ofmelamine. Specifically, condensation products such as N,N'bis(hydroxymethyl)ethylene urea, N,N bis- (methoxymethyl)ethylene ureaand dior tri-(methoxymethyl) melamine have given the best results. Verygood results, though not as good as those attainable with theaforementioned condensates, are obtained with such materials asdimethoxymethyl methylene diurea, dimeth oxymethyl urea, anddiandtrimethylol melamine. Such materials as dimethylolurea, the mixedmonomeric methylol compounds resulting from the reaction of 1.3 moles offormaldehyde and 1 mole of urea, i.e. mixed monomethylol and dimethylolurea, and the methyl ethers of such mixed monomeric methylol compounds,are also suitable but less eifective. Mixtures of the variousamidogen-formaldehyde condensates may be employed if desired.

When blends of regenerated cellulose fibers and cellulose acetate fibersare treated with the aforesaid amidogenformaldehyde condensates, thesecondensates tend to be absorbd preferentially on the regeneratedcellulose fibers. Accordingly, in this case the'process of thisinvention is somewhat less effective, with respect to the washfastnessof the dyed cellulose acetate portion of the blend, than when it isapplied to textile materials made entirely of cellulose acetate. It isfound that in the treatment of such blends best results are obtainedwhen at least a portion, preferably at least about 30%, of theamidogenformaldehyde condensate consists of a cyclic urea-formaldehydecondensation product, such as the N,N'-bis- (hydroxymethyl)ethylene ureaor its dimethyl ether, or a dior tri-(alkoxymethyl)melamine. Forexample, there may be employed a mixture comprising of N,N'-bis-(hydroxymethyl)ethylene urea and of N,N'-dimethoxymethyl urea or /2 ofN,N'-bis(hydroxymethyl)ethylene urea and /2 of N,N'-dimethylolurea or amixture comprising /2 of N,N*-bis(methoxymethyl)ethylene urea and /2 ofthe condensation product of urea, stearamide and formaldehyde. By usingmixtures of different amidogen-formaldehyde condensates and by changingthe proportions in such mixtures the hand and resilience of the finishedfabric may be varied, as desired.

The amidogen-formaldehyde condensation product is advantageously appliedto the textile material in the form of an aqueous'solution thereof. Itis preferable to apply this solution at a temperature not above about 30C. since may of the amidogen-formaldehyde condensates are unstable andtend to polymerize on prolonged exposure to elevated temperatures.However, if desired, the temperature of the solution may be higher, e.g.about 50 C., particularly when themore stable amidogem.

formaldehyde condensates are employed and the solution is not subjectedto the elevated temperature for long periods of time. The solution mayalso contain a swelling agent for the cellulose acetate or other organicderivatives of cellulose, such as, for example, the butyl ether ofethylene glycol, acetone or dioxane to improve the uniformity ofdistribution of the condensate in the textile material. Theconcentration of the solution and the amount thereof applied to thetextilematerial are desirably such as to incorporate into the textilematerial about 2 to 15%, preferably about 5 to by weight of theamidogen-formaldehyde condensate, based on the weight of the textilematerial.

As stated, a metal-containing chelating agent, preferably acopper-containing chelating agent, may be employed in conjunction withthe amine-formaldehyde condensate. While chelating agents which arecopper salts, e.g. copper acetate or copper sulfate, may be employed, itis often preferably to use those copper-containing chelating agentswhich contain copper combined with complex organic compounds, e.g. withreaction products of dicyandiamide and formaldehyde, or combinationssuch as disclosed in US. Patent No. 2,573,489. An example of a verysuitable chelating agent is the product sold under the name Cuprofix 47,which provides only relatively small amounts of free copper ion. Othercopper-containing chelating agents, containing larger amounts of copperions, e.g. those sold under the names Coprantex B and Resofix VF,'may beemployed'advantageously, par- 6 ticularly when fixablev direct dyes arepresent. The chelating agent may contain other metals, e.g. zirconium,nickel or chromium, instead of copper.

When a metal-containing chelating agent is employed it is preferablyincorporated into the aqueous solution containing theamidogen-formaldehyde condensate. One convenient method forincorporating this chelating agent is to dissolve it in 'water and mixthe solution with an aqueous solution of the amidogen-formaldehydecondensate. The amount of chelating .agent may be, for example, about 1to 3% by weight based on the weight of the textile material. i

As stated, a catalyst should be present during the reaction in the fiberbetween the amidogen-formaldehyde condensation product and the dyestuif.Suitable catalysts are those which are acidic at the temperature atwhich this reaction is carried out. A particularly effective catalyst isa mixture preparedby adding formaldehyde to ammonium chloride or to anamine hydrochloride in aqueous medium. The addition of the formaldehydeincreases the acidity, i.e. it causes the pH-of the aqueous mixture todrop sharply, e.g. from an initial value of 5.5 down to a value of 2.0.A very suitable catalytic mixture of this type is the one knownasCatalyst 6-8. Ammonium chloride, per se, is also a good catalyst. Othersuitable catalysts are ammonium sulfate and the amine hydrochlorideknown as Aerotex Accelerator 187. Other catalysts which may be used butwhich are less effective than those mentioned above are oxalic acid andthe alkanolamine hydrochloride known as Accelerator UTX. Advantageously,the catalyst is mixed into the aqueous solution of theamidogen-formaldehyde condensate. For example, a dilute aqueous solutionof the catalyst may be mixed with the aqueous solution of theamine-formaldehyde condensate just before the mixture is applied to thetextile material. Suitable proportions of the catalyst are about 2 to10%, preferably about 5 to 10%, by weight based on the weight of theamidogenformaldehyde condensate. Of course, if the dyedtextile materialcarries an alkaline material, e.g. asan impurity, such alkaline materialwill react with all or part of the catalyst thereby reducing theetfective amount of catalyst present. Accordingly, in such a case theamount of catalyst' actually applied to the textile material must beincreased to provide the desired effective amount thereof.

It is also found that the addition of formaldehyde to the aqueous bathcontaining the amidogen-formaldehyde resin effects a significantimprovement in the washfastness of the resulting treated dyed textilematerial. This is surprising since treatment of the dyed material withaqueous formaldehyde, together with an acidic catalyst but without theamidogen-formaldehyde condensate, causes no improvement in washfastness.The elfect of added formaldehyde is particularly pronounced when theaqueous treating bath contains a less reactive amidogenformaldehydecondensate, e.g. a condensate of urea and less than two moles offormaldehyde. However, a definite improvement is obtained by theaddition of formaldehyde to baths containing the more reactive of thecondensates, e.g. N,N bis(hydroxymethyl) ethylene urea.

Advantageously', the concentration of formaldehyde in the aqueoustreating bath, containing the amidogen-formaldehyde condensate, is aboutV2 to 5%. The formaldehyde is conveniently added to the treating bath inthe form of an aqueous solution thereof, e.g as a solution containingabout 40% of formaldehyde by' weight.

As stated,-the process of. this invention may be applied to textilematerials comprising blends of cellulose acetate and regeneratedcellulose fibers. It is well known that the 7 application ofamidogen-formaldehyde condensates to fibers of regenerated "celluloseincreases the resilience and resistance to shrinkage of the fibers buthas the disadvantages of reducing their abrasion resistance and tearstrength. In the process of this invention the latter disadvantages maybe overcome in large'part by the application of certain finishingagents,*s'uch as the silicones, e.g. those methyl hydrogenpolysilo'xancs known as De Cetex 102, 104, 108, or Hydropruf, or longaliphatic chain melamine compounds, such as the condensation products ofstearamide or stearylamine with melamine and formaldehyde. Thesefinishing agents are advantageously incorporated into the aqueoussolution containing the amidogen-formaldehyde condensate and inproportions sufiicient to provide 0.5 to 2% or more of such materialsbased on the weight of fabric. The use of these finishing agents alsoimparts durable water repellency to the textile material and results ina fabric which has a higher safe ironing point and animproved'resistance to shrinkage on pressing in the presence of moiststeam. The aliphatic melamine derivatives also improve the resistance ofthe dyed material to gas fading.

In one convenient method of practicing this invention a'fabriccomprising yarns of cellulose acetate is dyed in an aqueousdyeb'athcontaining one or more of the dyestuffs described above. Theamounts of the dyestuffs present in the dyebath are, of course,dependent on the type and depth of shade desired on thefabric. Thus, thetotal amount of dyestutf applied may be-about 0.2 to 6%, by weight,based on the weight of the fabric. In order to carry out the dyeingoperation at a relatively rapid rate the aqueous dyebath should bemaintained at an elevated temperature, e.g. at least about 75 C.,preferably about 80 to 90 C. Such elevated temperatures are particularlydesirable since many of the dispersedcellulose acetate dyestuffssuitable for use in this invention are of the high temperature slowdyeing type, which have a slow rate of dyeing onto cellulose acetate'atlower temperatures. If desired, the aqueous dyebath may be maintainedunder superatmospheric pressure so that the dyeing may be conducted attemperatures above the normal boiling point of said dyebath,particularly when fabrics of acetoneinsoluble cellulose acetate ofhigher acetyl value are employed. The dyestuffs should be well dispersedin the dyebath, e.g. in the conventional manner, by the use of asuitable surface active agent, so that a level and well penetrateddyeing is obtained. The dyeing operation may be carried out in anysuitable apparatus, such as a winch or a jig. After dyeing the fabricshould be rinsed thoroughly to remove any residual alkali, surfaceactive agent or unbound dyestuff and should be dried quickly to avoidany tendency for migration of the colors.

After drying, the dyed fabric is advantageously brought into contactwith an aqueous bath containing the amineformaldehyde condensate, thechelating or fixative agent, the catalyst and the finishing agent. Thisbath may be conveniently applied to the fabric by padding, for exampleby passing the fabric through the bath and then through the lower nip ofa bank of three pressure rolls, then again through said bath and throughthe upper nip of said bank of rolls. The amount of the aqueous bathpicked up by the fabric in the padder may be varied, e.g. from about 60to 125% based on the weight of the fabric. After the padding operationthe textile material is dried and then cured. Conveniently the drying iscarried out in a tenter at a temperature of, for example, 240 to 280 Fpreferably using some overfeed to the tenter to permit the textilematerial to relax. The dried fabric is then cured, e.g. at a temperatureof about 285 F. to 340 F. for a period of about 2 to minutes. After thecuring operation the fabric-is desirably "washed, preferably in thepresence of a mild detergent, to remove any residual acidity and preventthe development of odor. If desired, the fabric may be subjected to anysuitable mechanical treatment, such as calendering or button-breaking,to prevent mark-otf and to modify the hand of the fabric. The process ofthis invention is preferably applied to a fabric, e.g. a woven orknitted fabric. However, it is also applicable to textile material inany form, 2:. 'g. staple fibers, yarn or tow.

other desired o w The following examples are given to illustrate theinvention further.

Example I A woven fabric comprising a blend of by weight of celluloseacetate fibers and 50% by weight of viscose rayon fibers is treated toremove any starch adhering thereto and is then thoroughly scoured.Thereafter it is dyed in a brown shade on a winch, using an aqueousdyebath comprising 0.51% of disperse powder comprising the blue dyel-hydroxy-4-p-(fi-hydroxyethyDanilido- S-hydroxy-S-nitro anthraquinone,0.51% of disperse powder comprising 4-nitro-2,6-dichlorophenylazo 4'-bis(fi-hydroxyethyl)amino-2'-chlorobenzene, 0.14% of disperse powdercomprising about 40% of the azo red dye 4-nitro-2-methoxy phenyl azo4-bis(/8-hydroxyethyl) amino-2'-acetylamino benzene and about of sodiumlignosulfonate, 0.58% of Resofix Blue GL, a fixable blue directdyestuff, 1.08% of Cuprofix Yellow GL, a fixable yellow direct dyestuff,2.30% of Risofix Rubine BLN, a fixable red direct dyestulf, allproportions being based on the weight of the fabric. The dyebath alsocontains 3% of Igepon AP (the sodium salt of isethionic acid), 2% oftetra sodium pyrophosphate, and 10% of Glaubers salt, based on theweight of the fabric. At the start of dyeing the temperature of thedyebath is 50 C. Dyeing is continued for one hour during which time thetemperature is raised to 82 C. After dyeing, the fabric is rinsed well,dried immediately on a tenter frame, cooled, allowed to relax in ascutching pan, and then padded with a mixture comprising 15% of SandozResin EN (comprising as the active ingredient 50% of dimethylolurea),10% of Rhonite R-l (comprising as the active ingredient 50% ofN,N'-dihydroxymethyl ethylene urea), 3% of Cuprofix 47 (acopper-containing chelating agent), 1.5% of Catalyst G-8 (a mixture ofan organic amine hydrochloride with formaldehyde), 1% of Softener H (acationic type of softening agent) and the balance water. The paddingbath is prepared by dissolving Sandoz Resin EN and Rhonite R-l in waterat room temperature; dissolving the Cuprofix 47 in water at 60 to C. andthen cooling the resulting solution to room temperature; mixing thesetwo solutions together with the softener and finally adding thecatalyst. The fabric picks up 78% of its weight of this padding bath.The padded fabric is dried on a pin dryer at 275 F. for 4- minutcs andis then cured with relaxation for 7 minutes at 320 F. Thereafter thefabric is scoured at C. for 10 minutes, rinsed in hot water at 60 C. andrinsed in cold water and then dried.

Example I] Example I is repeated except that in place of the 10% ofRhonite R-l there are used 6% of a mixture comprising as the activeingredient 80% of N,N-dimethoxymethyl ethylene urea.

Example III Examples I and II are repeated with the followingexceptions: The blue and red disperse powders are used in the amounts of0.26% and 0.07%, respectively while the orange dyestufl is replaced by0.17% of a mixture disperse yellow powder comprising about 40% of2-nitrodiphenylamine-4-sulfonanilide and about 60% of sodiumlignosulfonate. The amounts of the blue, yellow and red direct dyestuffsare changed to 0.19%, 0.19% and 0.21%, respectively. The fabric is dyedgray.

Example IV Examples I, II and III are repeated except that the curing ofthe padded fabric is carried out at 340 F. for 2 minutes.

Example V Another .verysuitable padding recipe contains 7.50% of AerotexResin 801 (N,N-dimethoxymethyl urea),

assumes 15% of "Rhonite R-l, 3% of Cuprolix 52 (a coppercontainingcationic fixative agent), 4% of Hydropruf (a silicone finishing agent),1.5% of Cobelfix (zinc octoate which acts to catalyze the curing of theHydroprof), 1.5% of Catalyst 6-8, and the balance water.

Example VI Another very suitable padding recipe is similar to that ofExample V except that 3% of Permel is substituted for the Cobelfix" andHydropruf and ammonium sulfate is substituted for the Catalyst 6-8.

Example VII Example III is repeated except that the yellow dyestufi 2nitro diphenylamine 4 sulfon(N p hydroxyethyl)-anilide is substitutedfor the 2-nitro-diphenylamine- 4-sulfonanilide.

The fabrics produced according to the foregoing examples are subjectedto the #2 A.A.T.C.C. washfastness test, involving washing at 120 F.After five washings the fabrics showed practically no change in shade.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of our invention.

Having described our invention what we desire to secure by LettersPatent is:

1. Process for the treatment of textile materials comprising fibers ofan organic derivative of cellulose, which comprises dyeing said textilematerial with a dispersed cellulose acetate dyestuff containing aplurality of radicals selected from the group consisting of an NH;group, an alcoholic hydroxyl group and a phenolic hydroxyl group, thenapplying to the dyed textile material a mixture of formaldehyde and asoluble heat-curable condensation product of formaldehyde and a compoundcontaining a reactive NH group, said condensation product containing aplurality of radicals selected from the group consisting ofN-hydroxymethyl and N-lower alkoxymethyl radicals, and then heating saidtextile material to efiect a reaction between said dyestufi and saidcondensation product in said fibers.

2. Process as set forth in claim 1 in which said condensation product isselected from the group consisting of N,N'-dimethoxymethyl ethyleneurea, N,N'-dihydroxymethyl ethylene urea, trimethoxymethyl melamine anddimethoxymethyl melamine.

3. Process as set forth in claim 1 in which said dyestufi contains aphenolic hydroxyl group and an alcoholic hydroxyl group.

References Cited in the file of this patent UNITED STATES PATENTS2,338,728 McNally Ian. 11, 1944 2,364,726 Landolt Dec. 12, 19442,416,884 Schrciber Mar. 4, 1947 FOREIGN PATENTS 569,557 Great BritainMay 30, 1945

1. PROCESS FOR THE TREAMENT OF TEXILE MATERIAL COMPRISING FIBERS OF ANORGANIC DERIVATIVE OF CELLULOSE, WHICH COMPRISES DYEING SAID TEXILEMATERIAL WITH A DISPERSED CELLULOSE ACETATE DYESTUFF CONTAINING APLURALITY OF RADICALS SELECTED FROM THE GROUP CONSISTING OF AN NH2GROUP, AN ALCOHOLIC HYDROXYL GROUP AND A PHENOLIC HYDROXYL GROUP, THENAPPLYING THE DYED TEXTILE MATERIAL A MIXTURE OF FORMALDEHYDE AND ASOLUBLE HEAT-CURABLE CONDENSATION PRODUCT OF FORMDALDEHYDE AND COMPOUNDCONTAINING A REACTIVE-NH-GROUP, SAID CONDENSANTION PRODUCT CONTAINING APLURALITY OF RADICALS SELECTED FROM THE GROUP CONSISTING OFH-HYDROXYMETHYL AND N-LOWER ALKOXMETHYL RADICALS, AND THEN HEATING SAIDTEXTILE MATERIAL TO EFFECT A REACTION BETWEEN SAID DYESTUFF AND SAIDCONDENSATION PRODUCT IN SAID FIBRES.